Vibratory grain cleaner with feed and discharge means

ABSTRACT

A grain cleaner including, in series, an inlet manifold, vibrating apparatus, an outlet manifold and vertically extending chutes. The inlet manifold includes an opening at the top for receiving a mixture of grain and foreign matter and side walls converging downwardly toward outlets. The outlets being located at one side of the inlet manifold near the lower end, each one being constructed to feed a stream of the mixture to one of a plurality of superposed screening decks. The mixture flowing through the outlets may be individually regulated by pivotable gates disposed therein to give uniform flows to each deck. Each deck includes a screen superposed over a pan. Whole grains are retained above the screen and fines consisting of foreign matter, broken grains, and undersized grains fall through the pores of the screen onto the pan. A vibrator is operatively assembled to shake the box and its contents at an acceleration of at least four times that of gravity and to exert a throw on the fines which is adequate to cause them to strike the underside of the screen and dislodge any material blinding any of the openings. The outlet manifold includes two outlets from each deck. One outlet is disposed to receive the grain which is retained on the screen. The other outlet is disposed to receive the fines on the pan. A passage in the outlet manifold adjoins each of the outlets and baffles are provided therein to horizontally deflect the grain or fines into different vertically extending chutes. Below the outlet manifold, the chutes are structured to laterally deflect the grain in one direction and the fines in another direction whereby all the grain will empty into a single duct and the fines will empty into another single duct.

45 Aug. 1,1972

[54] VIBRATORY GRAIN CLEANER WITH FEED AND DISCHARGE MEANS [72]inventor: Louis E. Hubach, Aurora, Ohio [73] Assignee: W. S. TylerIncorporated, Mentor,

Ohio

22 Filed: Jan. 30, 1969 21 Appl.No.: 795,260

[52] U.S. Cl. ..209/240, 209/254, 209/317, 209/325, 209/381, 222/481[51] Int. Cl. ..B07b l/36, B07b 1/50 [58] Field of Search ..209/240,237, 323, 326, 315, 209/243, 379, 381, 382, 346,316, 236, 246, 317, 254,325; 222/481, 556, 564, 497-499,

[56] References Cited UNITED STATES PATENTS 440,301 1 H1 890 Boorman..209/347 695,654 3/ 1902 Sherman ..209/498 X 791,425 5/1905 Johnson..'.222/564 X 1,231,297 6/1917 Raber ..209/498 2,361,927 1 l/ l 944Buckman ..209/498 2,952,362 9/1960 Johnston ..209/498 X 497,343 5/ 1893Rasch ..209/240 X 552,749 l/l896 Curtis ..209/315 X 755,073 3/ 1904Sturteuant ..209/317 2,208,596 7/1940 Parks ..209/315 X 2,213,050 8/1940Reimuller ..209/254 X 2,995,245 8/ 1961 Titelboom ..209/243 X 3,232,4312/1966 Musschoot ..209/379 X 3,388,797 6/1968 Herman ..209/317 X3,392,491 7/1968 Vogt ..209/311 X 3,425,552 2/1969 Curtis ..209/317 X3,452,868 7/1969 Miller ..209/316 X FOREIGN PATENTS OR APPLICATIONS220,429 2/1959 Australia ..209/243 222,456 9/1909 Germany ..209/326298,059 7/1954 Switzerland ..209/316 425,482 3/1935 Great Britain..209/346 Primary Examiner-Frank W. Lutter Assistant Examiner-RobertHalper Attorney-Fay, Sharpe & Mulholland [57] ABSTRACT A grain cleanerincluding, in series, an inlet manifold, vibrating apparatus, an outletmanifold and vertically extending chutes. The inlet manifold includes anopening at the top for receiving a mixture of grain and foreign matterand side walls converging downwardly toward outlets. The outlets beinglocated at one side of the inlet manifold near the lower end, each onebeing constructed to feed a stream of the mixture to one of a pluralityof superposed screening decks. The mixture flowing through the outletsmay be individually regulated by pivotable gates disposed therein togive uniform flows to each deck. Each deck includes a screen superposedover a pan. Whole grains are retained above the screen and finesconsisting of foreign matter, broken grains, and undersized grains fallthrough the pores of the screen onto the pan. A

yibrator is operativel a ssembled to sh ke t e box and its contents atan a ce eratIon 0 at east our times that of gravity and to exert a throwon the fines which is adequate to cause them to strike the underside ofthe screen and dislodge any material blinding any of the openings. Theoutlet manifold includes two outlets from each deck. One outlet isdisposed to receive the grain which is retained on the screen. The otheroutlet is disposed to receive the fines on the pan. A passage in theoutlet manifold adjoins each of the outlets and baffles are providedtherein to horizontally deflect the grain or fines into differentvertically extending chutes. Below the outlet manifold, the chutes arestructured to laterally deflect the grain in one direction and the finesin another direction whereby all the grain will empty into a single ductand the fines will empty into another single duct.

12 Claims, 7 Drawing Figures [151 3,680,697 Aug. 1,1972

United States Patent Hubach D FINES ACCEPTABLE GRAIN 'OVERFLOWPATENTEDAUB 1 I972 SHEET 1 0F 4 FROM SCA LPER FIG. I

INLET MANIFOLD FIG.2

4 \6 E B H A RC T 0A B SWW WU CA H UWCR N AG E 6 0 w m 6 3 o L P BY ay,5W 8 Mulalland ATTORNEYS PATENTEDAUI; 1 I972 SHEET 2 [IF 4 FIG. 3

RH mm M H N E M s g w W O L 5 d 5 E F ATTORNEYS PATENTEmuc 1 I972 SHEET3 BF 4 INVENTOR. LOUIS E. HUBACH ATTORNEYS P'A'TENTl-fmuc' 1 m23.680.697- sum u or 4 E L D U MN L Tl T M R UN E 6 E CA W mm M A m we rF GM 4 INVENTOR. LOUIS E. HUBACH ACCEPTABLE 66 q GRAIN FINES BY 4a,,fiaapefi/Wulollaml ATTOR NEYS VIBRATORY GRAIN CLEANER WITH FEED ANDDISCHARGE MEANS BACKGROUND OF THE INVENTION A conventional graincleaning device includes a chute for feeding a mixture of grain andfines to a shaker box. Within the shaker box in the mixture flow path, aseries of spaced openings of equal size provide for gravitationaldivision of the mixture into a plurality of equal streams. The intent isto provide a uniform feed of material to each of a plurality ofscreening decks disposed in the box. Each of the decks includes a screenwith a pan disposed thereunder. The screen is provided withappropriately sized openings to retain the whole grains above the screenand allow the fines to fall onto the pan.

Near the end of each screen and disposed thereon is a baffle. The baffledirects the grain to one side of the screen where it is discharged to avertically extending chute. A similar baffle on the pan deflects thefines to the other side into a second vertically extending chute.

The first problem existing in the sequence of flow outlined above is theproper division of the flows of material to the screening decks toprevent choking of one screen and starving of another. Unfortunately,the plurality of spaced openings is inadequate to equally divide thegrain-fines mixture. Grain will not spread evenly on a flat surface in ashort distance; see U. S. Pat. No. 2,908,391 for an example of the priorart. The instant invention has solved the uniform feed problem byproviding an inlet or feeding manifold which has a uniform pressure headof grain applied to the various inlets to the screens and adjustablegates in each screen inlet to insure the uniform feeding of each screen.

The next problem in the sequence is the screen itself. Often the fineswill be very close to the size of the whole grain andwill pass partiallythrough the screen openings and remain lodged therein. This is called I"blinding" of the screen and prior art devices require frequentshutdowns to disassemble the screen and clean it by air blasts or othermeans.

It has been discovered that where the shaker apparatus has anacceleration of at least four times that of gravity applied thereto andwith a vertical throw of the material on the pan which is adequate tostrike the underside of the screen, the blinding is almost totallyeliminated because the material on the underside of the screen will tendto dislodge the materials blinding the pores. This improvement greatlyincreases the longevity of operation between the times of shutdown.

The next problem in the line of flow is the baffles disposed within theshaker box. As may be imagined, providing the baffles both above andbelow the screen tends to reduce its effective area. The baffles in theprior art usually extend at an angle of approximately 45 and this lostscreen space is shown to be an unnecessary waste by this invention. Itwas conceived that a separately assembled baffle structure in an outletmanifold on the end of each deck would be a proper solution to thisproblem. Thus, no part of the screen is blocked off from its primefunction. As a result, the total screen would be usable for separatinggrain from fine: and the previously discussed solution to the blindingproblem would inure throughout the screen rather than only part of thescreen. Therefore, the outlet manifold ha been provided at the end ofthe box with two openings for each deck, one for the fines and the otherfor the whole grain. Baffles are provided therein for deflecting thegrain into a plurality of vertically extending chutes and the finessimilarly are deflected into an appropriate plane for discharge intoother vertically extending chutes.

Another problem which exists in the prior art is the distance of thehorizontal grain deflection in the vibrating apparatus. The grain on oneside must be pushed half the width of the screen. It is inherent in thephysical structure of granular material to resist such movement. As aconsequence, much of the power of the vibrator is consumed in thishorizontal deflection. That excess consumption of power is largelyeliminated by the instant invention. First, the screening decks areinclined at an optimum angle; second, a plurality of verticallyextending chutes are provided which reduces the required horizontaldeflection; and third, at laterally deflecting structure is provided ineach grain chute to cause them to converge into a single duct. The grainexits from the outlet manifold and falls into the vertically extendingchutes by gravity. With the gravitationally imparted momentum, thelateral deflections within the chutes require no outside manufacturedpower, thus the expense of grain separation is reduced.

BRIEF DESCRIPTION OF THE INVENTION A chute feeds a mixture of grain andfines to inlet manifolds for a multi-deck screening apparatus. Anoverflow chute near the top of each manifold maintains a constantpressure head of grain therein. The inlet manifold is attached bysuitable structure to a box containing a plurality of screening decks. Asingle vibrator is provided for the two shaker boxes with one box aboveand one box below for structural balance. A plurality of outlets fromthe manifold are provided facing the shaker box screening apparatus anddisposed in each outlet is a pivotable gate for regulating the flowmaterial therethrough, thereby providing a means for insuring uniformflows of the mixture to each of the screening decks.

The multi-deck screens housed in the box are inclined at the optimumangle for conveying grain and adequately separating the mixture. Thescreens are vibrated by a shaking or vibrating means which is regulatedto vibrate the box with an acceleration of at least four times that ofgravity.

Each screening deck includes a pan with a superposed screen. The screenopenings are of a size to allow foreign matter, broken grains andundersized grains to pass therethrough and be deposited on the pan. Itis intended that whole grains remain above the screen. The vibratingapparatus imparts to the separated material on the pan a vertical throwadequate to have the material strike the underside of the screen anddislodge any materials which may tend to be deposited in the openings ofthe screen and blind the screening operation.

At the outlet end of the box is an outlet manifold. The outlet manifoldhas a plurality of openings at its inlet end to receive the materialfrom the screening decks. There are two inlets in the manifold for eachdeck, one to receive the whole grains from above the screen and one toreceive the fines from between the screenand the pan. Provided withinthe outlet manifold are a plurality of baffles for deflecting the grainsand the fines horizontally in opposite directions whereby the grain andfines from each of the screens or pans,

respectively, will exit from the outlet manifold into one of a pluralityof separate vertically extendingchutes. Material exiting from the outletmanifold will fall into a chute and acquire a momentum due to gravity. Asuitable distance below the outlet manifold in each chute is anangularly extending deflector. The grain and fines are laterallydeflected by these deflectors in opposite I directions, each into asingle, larger duct.

Another object is to provide an improved method of separating grain fromfines.

Another object is to provide a multi-deck grain separator inclined atthe optimum angle for moving and separating grain and fines.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a side elevational view of thecombination of this invention including a feeding manifold, a vibratingscreen housing, a discharge manifold and a plurality of verticallyextending chutes;

7 FIG. 2 is a perspective view of the feeding manifold, partially insection, showing the adjustable outlet openings; 7

FIG. 3 is a fragmentary elevational view, partially in section, ofthebox and the decks of separators therein;

FIG. 4 is an exploded view. of the elements of the outlet manifoldshowing the baffles for deflecting the separated grain and fines;

FIG. 5 is a fragmentary plan view of the screening area and the outletmanifold, partially in section;

FIG. 6 is a diagramatic view of the flow path of the grain and fines;and

FIG. 7 is an elevational view of the vertically extending chutes.

PREFERRED EMBODIMENT I This invention is related to a multi-deck graincleaner or separator .in general, and in particular to separators forcorn and soybeans. It includes a chute 10 for feeding mixtures of grainand fines to feeding manifolds or hoppers 12 and 13 which in turn feed avibrating apparatus 15. Substantially identical upper and lower shakerboxes or housings l4 and 16, respectively are secured together in spacedrelationship by this invention and any conventional vibrating mechanismmay be employed. At the outlet end of each of the shaker boxes is anoutlet manifold 20 which guides the separated material to a plurality ofoutlet chutes indicated generally at 22..

As the boxes are substantially identical, only one will be described.The mixture of grain and fines is fed into the feeding manifold 12through an inlet opening 24 at the top thereof. The bottom' wall 26 ofthe inlet manifold 12 is disposed adjacent the bottom edge of the shakerbox 14.

At the side of the inlet manifold 12, juxtaposed to the housing 14, area plurality of outlets 28. One outlet 28 is provided and aligned to feedeach of a plurality of screening decks 27 secured in the housing 14. Theoutlets 28 are disposed just above the screen 29 of each of thescreening decks 27 and to insure a uniform feed of grain and foreignmatter to each of said screening decks, gates 30 are provided withineach outlet. These gates 30 may be individually adjusted to prevent thechoking of one screening deck, and the starving of another or they maybe locked together for group adjustment, as desired. Each gate 30 ispivoted at 32 about an axis at one side edge extending perpendicular tothe direction of grain flow.

As best seen in FIG. 2, the edge of each gate 30, remote from the pivotaxis, is tapered to a sharp edge 33. The sharp edge facilitates the flowof grain past the gates and provides a definite dividing line betweenflow paths. Also, when separating com, the sharp edge will sever anycorn husks which may be in the stream, thereby preventing clogging.

In order to properly adjust the gates for continual uniform feed,-theremust be a constant pressure head of grain applied to the gates. As aresult of this fact, an intemal rear wall 34 is provided within theinlet manifold 12. Just above the internal rear wall 34 is an overflowopening 36 which feeds an overflow chute 38. The continual grainseparation process includes feeding the grain-fines mixture through theinlet opening 24 at a faster rate than the rate of exit from the outlets28. Thus, at all times there may be some material overflowing the inletmanifold 12 through the overflow opening 36 and into the overflow chute38 where it will be returned to the feed chute 10 or to storage bins(not shown). 7

It should be noted that the irregularity of the individual grains andtheir natural friction provides a back force within the inclinedbranches of the feed chute 10 whereby the effective grain pressure headin.

each inlet manifold may be measured from point 39, see FIG. 1. Point 39is the location in each branch where the grain has substantially astraight line drop into the inlet manifolds 12 and 13.

Resilient mountings 40 at each corner of the shaker boxes serve tosupport the separator above a substrate 41. Such mountings have beenfound convenient "for preventing the transfer of vibrations from theseparator to the supporting structure. I

Each of the decks 27 includes a screen 29 fixed in position above a pan46. Appropriate sealing devices 47 are provided along the edges of thescreen and the pan to prevent intermingling of the separated materials.The screen, per se, may be woven wire, a perforated sheet metal piece orsome woven cloth, depending upon the particular kind of separationdesired. The

word screen is intended to include any type of apparatus such as this,which is involved in a separating operation.

As is conventional, the screening decks 27 are encompassed in shakerboxes 14 and and are caused to vibrate by the vibrator 18. This agitatesthe grain and fines on the screen 29 and the fines tend to pass throughthe screen openings and be deposited on the pan 46. Moreover, in thisinvention, the vibrator 18 is regulated to impart an acceleration to theboxes 14 and 16 of at least four times that of gravity and the pan 46and screen 29 are so spaced and regulated with the vibrator 18 that avertical throw is imparted to the fines which is adequate to cause themto strike the underside of the screen 29 and dislodge any materials inthe openings which might tend to blind the screen. The spacing of thescreen 29 and the pan 46, the rotational velocity of the vibrator 18,etc. may be experimentally determined for'any particular sizes of grain,as necessary. In addition, the optimum angle of inclination, in therange l520, for the screening decks 27 should be determined. With manyof the ordinary grains, the deck should incline at about 17. When thegrain and fines arrive at the outlet end of the screening deck 27, it isanticipated that substantially all of the fines will have been separatedfrom the whole grains where the optimum angle is used.

Each deck has two outlets to the outlet manifold 20. An upper outlet 48is disposed immediately above the screen 29 for the grain. A loweroutlet .50 is provided between the screen 29 and the pan 46 forreceiving the separated fines.

Two passages are provided in the outlet manifold for each deck, one is agrain passage'52 and the other is a fines passage 54. Disposed in eachpassage are a plurality of baffles 56 which deflect the grain and fineshorizontally in different directions. The outlet passages and bafflesare uniformly disposed from deck to deck, whereby the deflections tendto direct the grain toward a passage of smaller cross-sectional areadownstream and eventually to a plurality of vertically extending chutes58 for receiving the separated cleaned grain and a plurality ofdifferent chutes 60 for receiving the fines which have been separatedfrom the grain. Thus, the elements making up vertically alternatepassages are in register.

In each of the chutes 58 and 60, below the outlet manifold 20, is anangularly inclined deflector 62. The deflectors in the grain chutes areinclined in one direction with the deflectors in the fines chutesinclined in another direction. This structure allows all the grainchutes 58 to empty into a larger single chute 64. Similarly, a singlechute 66 accommodates the discharge of all of the fines chutes 60. Theenlarged single grain chute 64 may extend to storage bins or elsewhere,as desired.

In operation, the vibrator 18 is actuated giving the two boxes 14 and 16an acceleration of at least four times that of gravity. A mixture offines and grain is continuously fed to the manifolds l2 and 13 throughthe chute 10. As the mixture flows into the manifolds, the outlets 28therefrom are adjusted to feed uniform streams of the mixture to each ofa plurality of superposed screening decks 27. As the screening decks 27are rigidly fixed within the boxes, they also receive an acceleration ofapproximately four'times that of gravity. The grain and foreign matteron the decks are agitated by the vibrating of the screens and the fines,including the foreign matter, broken grains and undersized grains willfall through'the screen opening onto a :pan46 located beneath thescreen. Grain is retained above the screen 29 because the openings arespecifically structured smaller than a normal sized grain of theparticular type being separated.

As the grain passes along the screen toward the outlet of the box,certain of the grains which are very close in size to the openingsthrough the screen may be lodged or trapped. To overcome this,correlation between the vertical throw of the vibrating apparatus andthe acceleration is regulated to toss the fines on the pan 46 upward tostrike anything which may be blinding any of the openings and adequatemomentum is imparted to the fines to dislodge anything which may betending to blind the screen. Passing on through the box, the separatedgrains exit into a passage in an outlet manifold which is immediatelyabove a similar passage which receives the separated fines.

The exits from the box take the separated materials intoan outletmanifold which is made up of a plurality of superposed passages forreceiving the grain and fines. Within each passageway through the outletmanifold are a plurality of baffles for deflecting material in ahorizontal direction. The grain will be deflected to oneside, the finesto the other side and the grain and fines will exit from the outletmanifold into one of a plurality of vertically extending chutes. Thefines will exit into certain chutes and the grain will exit into certainother chutes.

Gravity will carry the material in the chutes downward to deflectingapparatus within each chute. The grain will be deflected laterally toone side and the fines laterally to the other side. Each of the grainchutes merges into a larger single grain chute for receiving all of thegrain and a similar chute receives all of the discharge from the fineschutes. The grain in its single chute and the fines in its single chutemay be conducted to appropriate disposal or storage apparatus asdesired.

For ease of description, the principles of the invention have been setforth in connection with but a single illustrated embodiment. It isnotintended that the illustrated embodiment nor the terminology employed indescribing it be limiting inasmuch as variations in this embodiment maybe made by those of ordinary skill in the art without departing from thespirit of the invention. Rather it is desired that the invention berestricted only by the scope of the appended claims.

The invention claimed is:

1. A method of cleaning grain including the steps of:

feeding a mixture of grain and fines into an inlet manifold;

passing the mixture from the inlet manifold through inlets to amulti-deck separator, each deck including a screen superposed above apan and first and second outlets;

adjusting the size of each inlet to provide for an equal flow of themixture to each deck;

vibrating each deck with an acceleration of at least four times that ofgravity and with adequate vertical throw to (1) separate the fines fromthe grain by passing the fines through the screen to the pan and (2)impel fines against the underside of the screen to dislodge particlescaught in the screen openings and prevent blinding of the screen byfines; passing the grain to an outlet manifold through first outlets ofeach deck; deflecting the separated grain by a plurality of baffles anddischarging it into a first vertically extending chute of less widththan the decks; passing the separated fines on each pan into the outletmanifold through second outlets simultaneously with the discharge of thegrain through the ,first outlets, deflecting the fines by a plurality ofbaffles, and discharging them into a second verticallyextending chute ofless width than the decks. 2. A multi-deck grain separator with thedecks thereof being secured in stacked relationship within box means;

each deck including a screen related in superposed position to a pan; aninlet above each screen for receiving a mixture of grain and finesthereon; means for vibrating the box means and decks to separate thegrain from the fines and with an acceleration of at least four timesthat of gravity to prevent blinding of the openings in the screen bygiving the separated fines on the pan a vertical throw adequate toimpinge them against the underside of the screen to dislodge anymaterial blinding any screen opening; first and second outlets from eachdeck, the first outlet being above the screen to accommodate theseparated grain and the second outlet being between the screen and panto accommodate the fines; the outlets opening into a manifold, themanifold including one passageway for each outlet and including bafflesfor channeling the separated grain from each deck into a verticallyextending chute and for channeling the fines from the pan into anothervertically extending chute. 3. The separator of claim 2 including meansfor regulating the flow of grain to each inlet to provide substantiallyequal flow volumes to each screen.

4. Apparatus for separating grain from fines including in combination, afeeding manifold means, a box, a discharge manifold means, a pluralityof decks of grain separating means in the box and a shaker means;

- the decks being fixed within the box in superposed position and eachdeck including means for separating grain from fines;

said feeding manifold means being secured to the box and includingregulating means for substantially equally apportioning flows of grainto each deck;

. the shaker means vibrating the box and decks with an acceleration ofat least four times that of gravity for imparting a throw with avertical component to the undersized units on the pan, the throw beingsufficient to impel the undersized units against the underside of thescreen to dislodge particles caught in the screen openings and preventblinding of the screen; l

and the discharge manifold means being attached to the box for eceivin eseparated ain f th decks and for chan ie mg it into a irertic I? extending stationary chute.

5. The combination 'of'claim 4 wherein the discharge manifold meansincludes means for receiving the separated fines and for channeling thefines into a dif ferent vertically extending stationary chute. I

6. The combination of claim 4 wherein the feeding manifold meansincludes means for providing a substantially constant pressure head ofgrain to the regulating means of each deck.

7. Apparatus associated with the outlet end of a grain separator forcollecting plural streams of grain into a single stream and pluralstreams of fines into a difierent single stream including, 7

outlet manifold means for receiving superposed al ternate streams ofgrain and fines which are moving parallel,

means for propelling the grain and fines,

baffle means for horizontally deflecting each stream into a passage ofnarrowing cross-section, the downstream termini of the superposed grainpassages being in register and the downstream termini of the finespassages also being in register,

all termini being disposed to empty into one of a plurality ofvertically extending channels and all termini in register emptying intothe same channel, there being a plurality of parallely extending grainchannels and a plurality of parallely extending fine channels,

every other channel being for grain with the alternate channels beingfor fines,

means cormecting all said channels for grain and fines into twochannels, all the grain channels emptying into a different singlechannel. 1

8. The apparatus of claim 7 wherein the outlet manifold is attached to ashaker box and disposed within the box are a plurality of superposedscreening decks for separating grain from fines, each deck having oneoutlet for grain and one outlet for fines.

9. The apparatus of claim 8 wherein the means for propelling is avibrator which vibrates the box with an acceleration of at least fourtimes that of gravity and imparts to material in the screening deck avertical throw adequate to impel the undersized units against theunderside of the screen to dislodge particles caught in the screenopenings and prevent blinding of the screen. i

10. The apparatus of claim 9 wherein inlet manifold means affixed to thebox feeds a mixture of grain and fines in substantially equal quantitiesto each deck.

11. The apparatus of claim 8 wherein the decks are inclined at an anglein the range l520 to convey the grain and provide adequate separation.

12. The apparatus .of claim '11 wherein'the angle is approximately 17.

II! I! l

1. A method of cleaning grain including the steps of: feeding a mixtureof grain and fines into an inlet manifold; passing the mixture from theinlet manifold through inlets to a multi-deck separator, each deckincluding a screen superposed above a pan and first and second outlets;adjusting the size of each inlet to provide for an equal flow of themixture to each deck; vibrating each deck with an acceleration of atleast four times that of gravity and with adequate vertical throw to (1)separate the fines from the grain by passing the fines through thescreen to the pan and (2) impel fines against the underside of thescreen to dislodge particles caught in the screen openings and preventblinding of the screen by fines; passing the grain to an outlet manifoldthrough first outlets of each deck; deflecting the separated grain by aplurality of baffles and discharging it into a first verticallyextending chute of less width than the decks; passing the separatedfines on each pan into the outlet manifold through second outletssimultaneously with the discharge of the grain through the firstoutlets, deflecting the fines by a plurality of baffles, and dischargingthem into a second vertically extending chute of less width than thedecks.
 2. A multi-deck grain separator with the decks thereof beingsecured in stacked relationship within box means; each deck including ascreen related in superposed position to a pan; an inlet above eachscreen for receiving a mixture of grain and fines thereon; means forvibrating the box means and decks to separate the grain from the finesand with an acceleration of at least four times that of gravity toprevent blinding of the openings in the screen by giving the separatedfines on the pan a vertical throw adequate to impinge thEm against theunderside of the screen to dislodge any material blinding any screenopening; first and second outlets from each deck, the first outlet beingabove the screen to accommodate the separated grain and the secondoutlet being between the screen and pan to accommodate the fines; theoutlets opening into a manifold, the manifold including one passagewayfor each outlet and including baffles for channeling the separated grainfrom each deck into a vertically extending chute and for channeling thefines from the pan into another vertically extending chute.
 3. Theseparator of claim 2 including means for regulating the flow of grain toeach inlet to provide substantially equal flow volumes to each screen.4. Apparatus for separating grain from fines including in combination, afeeding manifold means, a box, a discharge manifold means, a pluralityof decks of grain separating means in the box and a shaker means; thedecks being fixed within the box in superposed position and each deckincluding means for separating grain from fines; said feeding manifoldmeans being secured to the box and including regulating means forsubstantially equally apportioning flows of grain to each deck; theshaker means vibrating the box and decks with an acceleration of atleast four times that of gravity for imparting a throw with a verticalcomponent to the undersized units on the pan, the throw being sufficientto impel the undersized units against the underside of the screen todislodge particles caught in the screen openings and prevent blinding ofthe screen; and the discharge manifold means being attached to the boxfor receiving the separated grain from the decks and for channeling itinto a vertically extending stationary chute.
 5. The combination ofclaim 4 wherein the discharge manifold means includes means forreceiving the separated fines and for channeling the fines into adifferent vertically extending stationary chute.
 6. The combination ofclaim 4 wherein the feeding manifold means includes means for providinga substantially constant pressure head of grain to the regulating meansof each deck.
 7. Apparatus associated with the outlet end of a grainseparator for collecting plural streams of grain into a single streamand plural streams of fines into a different single stream including,outlet manifold means for receiving superposed alternate streams ofgrain and fines which are moving parallel, means for propelling thegrain and fines, baffle means for horizontally deflecting each streaminto a passage of narrowing cross-section, the downstream termini of thesuperposed grain passages being in register and the downstream terminiof the fines passages also being in register, all termini being disposedto empty into one of a plurality of vertically extending channels andall termini in register emptying into the same channel, there being aplurality of parallely extending grain channels and a plurality ofparallely extending fine channels, every other channel being for grainwith the alternate channels being for fines, means connecting all saidchannels for grain and fines into two channels, all the grain channelsemptying into a different single channel.
 8. The apparatus of claim 7wherein the outlet manifold is attached to a shaker box and disposedwithin the box are a plurality of superposed screening decks forseparating grain from fines, each deck having one outlet for grain andone outlet for fines.
 9. The apparatus of claim 8 wherein the means forpropelling is a vibrator which vibrates the box with an acceleration ofat least four times that of gravity and imparts to material in thescreening deck a vertical throw adequate to impel the undersized unitsagainst the underside of the screen to dislodge particles caught in thescreen openings and prevent blinding of the screen.
 10. The apparatus ofclaim 9 wherein inlet manifold means affixed to the box feeds a mixtureof grain and fiNes in substantially equal quantities to each deck. 11.The apparatus of claim 8 wherein the decks are inclined at an angle inthe range 15*-20* to convey the grain and provide adequate separation.12. The apparatus of claim 11 wherein the angle is approximately 17*.